O-360 A1A Question

I have finished the 40 hours on my 6 and I'm having a great time flying it. I now have 50 hours on the engine. It is running great though I have fouled a couple a plugs. My guru buddies tell me that's normal for a new engine. It's burning oil and fouling the lower plugs. supposedly it will clear up?

My question is on the mag wiring on the O-360 A1A in my 6. According to the spark plug wiring diagram in the book, the left mag goes to the lower plugs on the left side and the upper plug on the right. The right mag of course goes to the lower right plugs and the upper left ones. My engine is reversed. Now when I look at some other pictures in the book it shows the wiring reversed as I have it on my engine. My question: does it matter! Should I re-route my spark plug wires? Which way should it be? Could this be fouling plugs? I highly doubt it, but?

We can guess and say you need to lean agressively on the ground to avoid fouling But that's just a guess until you pull a plug or two and take a look and see what it looks like.

I definitely would not bother with those wires.. that won't cause fouling and I don't see any issues with having it the way you got it there..

Depending on what's going on, you may wanna consider 37BY plugs, but they may not be needed if you lean more on the ground etc..

Wires shouldn't make a difference for fouling. When you pull the plugs, whats on them? Oil? Lead?

Lycoming 0360-A1A

I had no problem with my Mattatuck assembled XP 360. I broke it in with Mineral oil as advised and it burned no oil so at their sugguestion switched to 10/50 at approx 10 hours. I never had any oil burn or plugs fowling. I did change oil every 25 hours or less. Roger Moore

Oil

It looks like oil on the plugs when I pull them. I found the two on the left side were wet once and it was running rough. I changed them out and then about 20 hours later one of the bottom left plugs are wet again. I just changed all the bottoms again yesterday. When I'm in the air and the plugs are fouled it seems to momentarily sug and surge. it's almost like you shut one mag off while flying, though not as dramatic. I can play with the mixture and kind of clear it up, but it's touchy getting it right. It seems to want it much richer than where I would set it normally. With new plugs she runs great again.

What heat range plugs are you using? You could try to go to the next hottest plug, or fine wires. Oil fouling isn't likely to get any better.

If you have quite a magneto drop between the two mags; do you ever rev up the engine and lean until it runs rough for a few seconds (on the ground)?This will burn the oil off the plugs. I had this happen a few times in my first 40 hours, but now lean more aggressively; and it hasn't happened since. I do fly out of a 4600' msl airport, though.

L.Adamson --- RV6A/ 0360 A1A

plugs and mags

My airplane is wired right mag to #1/3 lower and #2/4 upper. Can't see why reverse would matter, i.e. left mag to those plugs.

How much oil are you using? At 50 hrs it should only use less than a quart in 10 hrs. If it is using more than that you have a ring or valve guide problem. Are the cylinders new or overhauled? My ECI cylinders broke in in less than 5 hours and only uses a quart every 20-25 hrs. Don

If your engine is burning oil, yoiu can't do anything about that except fix the problem, or hope it fixes itself.
However, there are a few things you can do to make the problem a little more liveable.
The easiest is to taxi with the mixture out almost to idle cut-off. If you are on an airport such as ours, you might have to taxi for a while. This will help.
The best partial fix is to change to fine wire plugs, which are expensive, but there are a few ways to approach this.
The first set I ever bought were Champions (now selling in the $80 each range), but I used that same set in 3 engines, and when I sold the plane, they were still in the engine.
The set I have in the -9A now are Unison, almost half the price.
Your engine would have to be really in bad shape to make these plugs foul.
If money is an issue, then just buy 4, and put them in the bottom holes.
When I first started flying the new engine, it had the standard massive electrode plugs, and even though my engine was consuming very little oil, the bottom plugs were fouling. Switched to the Unison fine wire, and never had a plug foul since. I still taxi with mixture way out.
Hope this helps.
Jack
RV9A
100 hours